Group differences in computer supported collaborative learning: Evidence from patterns of Taiwanese students’ online communication

This study explored the differences among online elementary school student groups based on their communication features. Two hundred and ninety-one Taiwanese students, ranging in age from 11 to 12 years old, participated in this study. The students were randomly arranged within-class into three-member groups. Each group was asked to use a collaborative learning system to accomplish a group task generating a shared concept map. The textual discussions in each group during collaboration were collected, coded, categorized, and quantified to profile their communication characteristics. Cluster analysis on the resulting communication characteristics resulted in four types of small student groups, including passive or reticent, frequently off-task, actively participating, and knowledge emphasizing. Most student groups (56%) were found to be relatively passive or reticent. Frequently off-task student groups made a protrusive amount of messages for off-task social purposes. The actively participating student groups were characterized by abundant discussion, particularly for continuing task, managing procedure and coordinating efforts. The distinctive feature of knowledge emphasizing student groups was that they devoted particular attention to task related knowledge. In addition, they performed better in task accomplishment.     

Technology management and strategy composition: innovation of IC foundry

The goals of this research are two-tiered: The first goal is to analyze the evaluation criteria used by integrated circuit (IC) designers when selecting foundry service providers. The second goal is to use an in-depth case study on the global IC foundry leader, TSMC, to explore the strategic compositions of IC foundry’s process development, since the process technology has been found, through our survey at the prior stage, to be the most significant evaluation criterion in view of competitiveness in the customer market. As a result, for the foundry industry, technology no longer counts for everything, although it is a priority; coordinated strategies, in contrast, should assure more business merits for all concerned. This study has drawn the strategy matrix with eight categories of IC foundry process strategies.     

Functional levels of floor surface roughness for the prevention of slips and falls: Clean-and-dry and soapsuds-covered wet surfaces

Literature has shown a general trend that slip resistance performance improves with floor surface roughness. However, whether slip resistance properties are linearly correlated with surface topographies of the floors or what roughness levels are required for effective slip resistance performance still remain to be answered. This pilot study aimed to investigate slip resistance properties and identify functional levels of floor surface roughness for practical design applications in reducing the risk of slip and fall incidents. A theory model was proposed to characterize functional levels of surface roughness of floor surfaces by introducing a new concept of three distinctive zones. A series of dynamic friction tests were conducted using 3 shoes and 9 floor specimens under clean-and-dry as well as soapsuds-covered slippery wet environments. The results showed that all the tested floor-shoe combinations provided sufficient slip resistances performance under the clean-and-dry condition. A significant effect of floor type (surface roughness) on dynamic friction coefficient (DFC) was found in the soapsuds-covered wet condition. As compared to the surface roughness effects, the shoe-type effects were relatively small. Under the soapsuds-covered wet condition, floors with 50?μm in Ra roughness scale seemed to represent an upper bound in the functional range of floor surface roughness for slip resistance because further increase of surface roughness provided no additional benefit. A lower bound of the functional range for slip resistance under the soapsuds-covered wet condition was estimated from the requirement of DFC?>?0.4 at Ra???17?μm. Findings from this study may have potential safety implications in the floor surface design for reducing slip and fall hazards.     

The effect of the guiding directions of the guiding cylinders of an area ratio modified machine cushion on the capability of suppressing impact and vibration

A machine cushion reduces the impact force and vibration waves from a machine to the ground and vice versa. In this study, we design machine cushions based on the concepts of wave guiding and suppression and with structures called “area ratio modified” (ARM) structures. The guiding direction of the internal guiding cylinders is one major factor that affects the machine cushion’s capabilities to absorb impact and suppress vibration. In order to compare and further investigate the machine cushion’s capabilities and limitations, we designed a simple, passive machine cushion as well as three ARM machine cushions, each with a different guiding direction of its internal guiding cylinders. Simulation results show that the ARM machine cushion with cylinders guided vertically upward has the best impact suppression capability. The derived dynamic equations and the simulation results obtained can be used also for evaluating the feasibility and limitations of machine cushion design in the future.     

A Sensor Network Web Platform Based on WoT Technology

This study proposes a Web platform, the Web of Things (WoT), whose Internet of Things (IoT) architecture is used to develop the technology behind a new standard Web platform. When a remote sensor passes data to a microcontroller for processing, the protocol is often not known. This study proposes a WoT platform that enables the use of a browser in a mobile device to control a remote hardware device. An optimized code is written using an artificial intelligence-based algorithm in a microcontroller. Digital data convergence technology is adopted to process the packets of different protocols and place them on the Web platform for access by other mobile devices. The platform has high efficiency and cross-platform advantages, with no limitation on the operating system. Message queueing telemetry transport (MQTT) technology is used to simplify the original HTTP protocol. Assume that the mobile device is a subscriber, i.e., the controller, and a microcontroller that connects the sensing device is the publisher. The publishers and subscribers of MQTT need not know each other if they share a message broker. The intermediate agent role is much like a router. Publishers and subscribers do not need to interact, and publishers do not have to wait for subscriber confirmation to cause interactive permission be locked. Nor must publishers and subscribers be online at the same time, and they are free to choose when to get messages. The proposed WoT method is compared with the traditional IoT method regarding data transfer. The results show that the proposed method can save time in processing large amounts of data, as the traditional IoT method wastes time, especially in data format transfer.     

Effects of screen size and visual presentation on visual fatigue based on regional brain wave activity

Advances in information technologies have resulted in people spending increasing amounts of time staring at electronic screens. Long-term use of computers, mobile phones, and tablets can cause eye soreness and fatigue, but can also cause more serious conditions including myopia, cataracts, and glaucoma. This study assesses changes in brain wave activity detected by eight electrodes targeting different brain regions to identify and assess the brain wave patterns in the regions associated with visual fatigue under various visual presentation methods. Furthermore, linear discriminant analysis and Min–Max scaling techniques are applied to develop a visual fatigue assessment model to quantify visual fatigue. Finally, experiments are run to assess the impact of screen size (smartphone, tablet, computer) and visual presentation mode (2D, 3D, AR, VR) on visual fatigue. This study finds that (1) the brain wave features which influence the reaction to 2D and 3D imaging are the delta and theta waves at the prefrontal Fp1 and Fp2 poles. When viewing AR images, the alpha bands at the O1 and O2 poles of the occipital lobe show a relatively clear impact, while the delta and theta waves at the C3 pole in the left center area are associated with VR images; (2) larger screens cause greater visual fatigue, indicating that excessive visual stimulation will increase visual loading and thus produce greater visual fatigue; (3) the results show that VR can cause quite severe visual fatigue, along with motion sickness passed on sensory mismatch. Therefore, it is recommended to avoid viewing experiences that are inconsistent with the brain’s physiological experience, such as walking while viewing a mobile phone, or reading in a moving car. The proposed visual fatigue assessment model provides easy and objective quantification of visual fatigue indicators, contributing to the reduction of risk for eye injury and disease.

     

Dissipative control for a class of uncertain nonlinear control systems

A general dissipative controller is proposed to achieve robust tracking control performance for a class of uncertain single‐input single‐output (SISO) nonlinear systems. The feedback linearization technique is employed to transform the nonlinear system into an assignable inner linear system with a differential control input so that the relationship of the external (input) power and the stored energy of system can be shown clearly. Then, a dissipative controller with an assignable attenuation level is proposed to make the system energy dynamics fit a required dissipative inequality. The unstable factors of the system can then be attenuated accordingly. The system stability is guaranteed even if the system has permanent unavoidable uncertainties. The proposed design can be achieved without the use of traditional means, i.e. optimal control, which requires solution of a Hamilton inequality (or Riccati equation). The Lyapunov stable condition is assured in our approach when the system uncertainties belong to L _∞. Moreover, due to the compatibility of the proposed controller, the controller can be embedded into the designs of other controllers. In those designs, knowledge of the system functions is not required. Basically, the proposed dissipative controller is independent of the system functions. The use of the bounds of the system function is considered to prove the system stability only. Two simulations are given to illustrate the effectiveness of the proposed controller. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Intelligent Home Using Fuzzy Control Based on AIoT

The Internet of Things has grown rapidly in recent years, and the technologies related to it have been widely used in various fields. The idea of this paper is to build a set of Internet of Things systems in a smart home wireless network environment, with the purpose of providing people with a more comfortable, convenient, and safe life. In the sensing layer of the Internet of Things, we discuss the uses of common sensing technologies on the Internet and combine these with Arduino microprocessors to integrate temperature sensing modules, humidity sensing modules, gas sensing modules, and particulate matter 2.5 (PM2.5) sensing modules. In the network layer, we discuss using the Wi-Fi wireless networking function composed of a home router and a wireless Wi-Fi chip Espressif system 8266 (ESP8266) to transmit the collected home-sensing data to the ThingSpeak cloud database. Finally, in the application layer part, the system uses a mobile device with fuzzy calculation optimization software. The system is also connected remotely for home environment monitoring, so the home environment can be optimized anytime, anywhere.     

Preservice and inservice teachers' pedagogical reasoning underlying their most-valued technology-supported instructional activities

We examined teachers' pedagogical reasoning for and the technological knowledge underlying their most-valued technology-supported activities for teaching and learning. Data from 140 preservice and 100 inservice teachers included open-ended, narrative responses to survey questions. Qualitative research methods guided analysis of the data that identified (a) the technology-supported activities and (b) the technical tools, target users, types of uses, rationales for use, and the TPACK underlying each activity. Preservice teachers described mostly teacher-focused and fewer student-focused techno-activities, and their reasoning for use focused on the technology's presentational and engagement effects. A majority of inservice teachers' techno-activities were student-focused, and their reasoning highlighted the technology's support for knowledge acquisition of higher-order cognitive skills and collaborative learning. The knowledge underlying all teachers' techno-activities was predominantly technological pedagogical knowledge (TPK), but inservice teachers also evidenced technological content knowledge (TCK). These results may reveal differences in the teachers' respective learning experiences in teacher education and professional development or reflect a professional maturation process in that it takes teachers time in the field as professionals to broaden their techno-activity repertoires to prioritize student-focus. Sharing the reasoning patterns in this study with teachers may assist them in developing deeper justifications for their technological work in the classroom.     

Optimization and comparison of photonic crystal resonators for silicon microcantilever sensors

Microcantilever sensors have been known as a fundamental design used in force sensors, strain sensors and biochemical sensors. The fast-growing applications in nanoelectromechanical systems (NEMS) lead to strong demands in new sensing mechanism in order to downsize the sensing elements to nanometer scale. Photonic crystal (PC) based resonators have been investigated as promising solutions because the bandgap structure and resonator characteristics are extremely sensitive to the deformation and position shift of holes in PC resonators. In addition to the well-known nano-cavity resonator (NCR), we proposed hexagonal nano-ring resonators (NRR) of two different layout configurations. When a microcantilever under different force loads, both of the resonant wavelength and the resonant wavelength shift can be measured as a linear function of force load. The linear relationship between wavelength shifts and strain is observed as well. The minimum detectable force and detectable strain for NRR configuration 1 is derived as small as 0.0757 μN and 0.0023%. The outstanding sensing capability renders PC resonators as a promising nanomechanical sensing element to be integrated in various transducers for NEMS applications.